Hi Steve, I've been experimenting with this a lot over the last two months and now have two clients currently using the solution so in short "yes, you can do what you're talking about". It's super-cool. One thing to watch for: the main workflow (the one that triggers the others) has to end when the child workflows run - you can't use the 'wait' action in the main workflow to wait for the child workflows to complete because if you do that you end up with multiple instances of the main workflow completing. So, for example, if you had the main workflow trigger 5 child workflows, when those 5 child workflows finished the main workflow would complete 5 times, one for each child. It took me a bit to figure out that was happening. Fortunately, there's an easy solution: split the main workflow so it does this:
1. main workflow does it's thing and then triggers child workflows
2. child workflows complete
3. the completion of all child workflows trigger another separate workflow (which is actually the end part of the original main workflow)
Let me know if you need more info and I can let you know how I've done the triggering and whatnot to make it all work.